Many patients with localized pain due to arthritis, bursitis, sprain or muscle strain, bruises or hematomas cannot tolerate conventional nonsteroidal anti-inflammatory drugs, commonly known as NSAIDS. In addition, topical administration of conventional NSAIDS has largely been ineffective because only a therapeutically ineffective amount of the drug can penetrate the skin. In addition, indications such as acne, psoriasis and eczema are typically refractory to topical or oral administration of NSAIDS.
Bromelain is a protease composition that is isolated from pineapple. The composition has been reported to have anti-inflammatory activity when administered orally or parenterally (see Taussig, S. J., "The mechanism of the physiological action of Bromelain", Medical Hypotheses, 6; 99-104, 1980). Commercially available bromelain used in the manufacture of pharmaceuticals is not a chemically homogeneous substance, but the principal component is a proteolytic enzyme that is a glycoprotein. The molecular weight of the protease in bromelain is approximately 33,000 Daltons.
Capsaicin is an oleoresin obtained by extracting cayenne pepper with ether. The synthetic capsaicin is trans-8-methyl-vanillyl-6-nonenamide. Capsaicin gels have been described in U.S. Pat. No. 5,178,879 as being effective in treating topical pain. In addition, capsaicin is available commercially in over-the-counter compositions intended for pain relief including lotions such as HEET, OMEGA OIL, SLOAN'S LINIMENT and ZOSTRIX.
Bromelain has been reported to be an anti-inflammatory agent, an inhibitor of platelet aggregation, an agent that increases proteolytic and fibrinolytic activity in blood, and as a selective prostaglandin inhibitor. Bromelain has been administered by injection and has been reported to be effective after oral administration. However, because bromelain is a macromolecule, it cannot be administered transdermally using prior art formulations.
What is needed is an anti-inflammatory composition that is effective in treating a wide variety of inflammatory conditions by topical application of the composition. The anti-inflammatory composition should not have the side effects associated with prior art non-steroidal anti-inflammatory agents.